Employing covalent organic frameworks (COFs) for the photocatalytic CO2 reduction reaction (CDRR) to generate high-value chemical fuels and mitigate greenhouse gas emissions represents a sustainable catalytic conversi...
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Employing covalent organic frameworks (COFs) for the photocatalytic CO2 reduction reaction (CDRR) to generate high-value chemical fuels and mitigate greenhouse gas emissions represents a sustainable catalytic conversion approach. However, achieving superior photocatalytic CDRR performance is hindered by the challenges of low charge separation efficiency, poor stability, and high preparation costs associated with COFs. Herein, in this work, we utilized perfluorinated metallophthalocyanine (MPcF16) and the organic biomolecule compound ellagic acid (EA) as building blocks to actualize functional covalent organic frameworks (COFs) named EPM-COF (M = Co, Ni, Cu). The designed EPCo-COF, featuring cobalt metal active sites, demonstrated an impressive CO production rate and selectivity in the photocatalytic CO2 reduction reaction (CDRR). Moreover, following alkaline treatment (EPCo-COF-AT), the COF exposed carboxylic acid anion (COO-) and hydroxyl group (OH), thereby enhancing the electron-donating capability of EA. This modification achieved a heightened CO production rate of 17.7 mmol g(-1) h(-1) with an outstanding CO selectivity of 97.8% in efficient photocatalytic CDRR. Theoretical calculations further illustrated that EPCo-COF-AT functionalized with COO- and OH can effectively alleviate the energy barriers involved in the CDRR process, which facilitates the proton-coupled electron transfer processes and enhances the photocatalytic performance on the cobalt active sites within EPCo-COF-AT.
N-2 reduction reaction (NRR) by light is an energy-saving and sustainable ammonia (NH3) synthesis technology. However, it faces significant challenges, including high energy barriers of N-2 activation and unclear cata...
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N-2 reduction reaction (NRR) by light is an energy-saving and sustainable ammonia (NH3) synthesis technology. However, it faces significant challenges, including high energy barriers of N-2 activation and unclear catalytic active sites. Herein, we propose a strategy of photo-driven ammonia synthesis via a proton-mediated photoelectrochemical device. We used redox-catalysis covalent organic framework (COF), with a redox site (-C=O) for H+ reversible storage and a catalytic site (porphyrin Au) for NRR. In the proton-mediated photoelectrochemical device, the COF can successfully store e(-) and H+ generated by hydrogen oxidation reaction, forming COF-H. Then, these stored e(-) and H+ can be used for photo-driven NRR (108.97 umol g(-1)) under low proton concentration promoted by the H-bond network formed between -OH in COF-H and N-2 on Au, which enabled N-2 hydrogenation and NH3 production, establishing basis for advancing artificial photosynthesis and enhancing ammonia synthesis technology.
Developing technology of artificial photosynthetic CO2 reduction is essential to improve the issues of global carbon emissions and climate change. However, it is still limited by the low charge separation efficiency a...
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Developing technology of artificial photosynthetic CO2 reduction is essential to improve the issues of global carbon emissions and climate change. However, it is still limited by the low charge separation efficiency and poor transport capacity of photocatalysts. Herein, two novel morpholine-linked metal-phthalocyanine COFs, Co-DA-COF and Co-DB-COF, were synthesized through the nucleophilic aromatic substitution reaction of cobalt perfluorophthalocyanine (CoPcF16) with 2,5-phenylenediamine-1,4-diphenol (DHA) and 3,3 '-dihydroxybenzidine (DHB). The introduction of morpholine bonds and the specific photosensitivity of metal phthalocyanines resulted in remarkable photocatalytic CO2 reduction reaction (CDRR) activity. Notably, Co-DB-COF exhibited enhanced electron delocalization owing to its expanded pi-conjugated system, which facilitated the process of separating and transporting photogenerated charge carriers. This resulted in a notable rate of CO production of 25.7 mmol g-1 h-1, exhibiting a selectivity of 92.3% and an AQE of 0.65% at 450 nm, which surpasses the majority of previously documented visible-light-driven COF-based photocatalysts. This work demonstrated the capability of morpholine-linked metal-phthalocyanine COFs in CO2 photocatalytic conversion, providing fresh insights for designing novel artificial photosynthesis catalysts.
Molecular engineering of covalent organic frameworks (COFs) offers an alternative approach to conventional anthraquinone oxidation via photo-induced H2O2 production from O2 reduction. Despite their potential, reported...
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Molecular engineering of covalent organic frameworks (COFs) offers an alternative approach to conventional anthraquinone oxidation via photo-induced H2O2 production from O2 reduction. Despite their potential, reported photocatalysts suffer limited proton mobility, low selectivity, and insufficient charge separation and utilization. Herein, we report a nitroxyl radical (TEMPO) decorated two-dimensional (2D) donor-acceptor (D-A)-COF photocatalyst via a one-pot strategy. Under visible light irradiation, highly crystalline TAPP-TPDA-TEMPO-COF (TT-T-COF) exhibits a remarkable photocatalytic H2O2 yield of 10066 mu mol g-1 h-1 in two-phase water-benzyl alcohol (10 % BA) system through direct two-electron (2e-) pathway. The mechanistic study by DFT calculations and in situ DRIFT spectra suggests Yeager-type adsorption of *O2 & sdot;- intermediate on the nitroxyl radical site (N-O & sdot;). The efficient photocatalytic performance and stability of TT-T-COF are attributed to the involvement of the nitroxyl radical, which enhances selective O2 adsorption, establishes a distinct electron density distribution, and facilitates photogenerated charge separation compared to TT-HT-COF and TT-COF counterparts. This study uncovers a new perspective for constructing metal-free, redox-mediated radical-based COFs for sustainable energy conversion, storage, and biomedical applications.
N 2 reduction reaction (NRR) by light is an energy-saving and sustainable ammonia (NH 3 ) synthesis technology. However, it faces significant challenges, including high energy barriers of N 2 activation and unclear ca...
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N 2 reduction reaction (NRR) by light is an energy-saving and sustainable ammonia (NH 3 ) synthesis technology. However, it faces significant challenges, including high energy barriers of N 2 activation and unclear catalytic active sites. Herein, we propose a strategy of photo-driven ammonia synthesis via a proton-mediated photoelectrochemical device. We used redox-catalysis covalent organic framework (COF), with a redox site (−C=O) for H + reversible storage and a catalytic site (porphyrin Au) for NRR. In the proton-mediated photoelectrochemical device, the COF can successfully store e − and H + generated by hydrogen oxidation reaction, forming COF−H. Then, these stored e − and H + can be used for photo-driven NRR (108.97 umol g −1 ) under low proton concentration promoted by the H-bond network formed between −OH in COF−H and N 2 on Au, which enabled N 2 hydrogenation and NH 3 production, establishing basis for advancing artificial photosynthesis and enhancing ammonia synthesis technology.
The high trap density (generally 1016-1018 cm-3) in organic solar cells (OSCs) brings about the localization of charge carriers and reduced charge carrier lifetime, mainly due to the weak intermolecular interactions o...
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The high trap density (generally 1016-1018 cm-3) in organic solar cells (OSCs) brings about the localization of charge carriers and reduced charge carrier lifetime, mainly due to the weak intermolecular interactions of organic semiconductors resulting in their relatively poor crystallinity, which leads to low charge carrier mobilities and intense non-radiative recombination, thus impeding the further improvement of power conversion efficiencies (PCEs). Therefore, trap suppression is crucial to boost the performance of OSCs, and improving the crystallinity of donor/acceptor materials and enhancing the molecular order in devices can contribute to the trap suppression in OSCs. In this feature article, we summarize the recent advances of trap suppression in OSCs by material design and device engineering, and further outline possible development directions for trap suppression to enhance PCEs of OSCs. High trap density in organic solar cells leads to the localized charge carrier and reduced carrier lifetime, limiting device efficiency. Here we summarize the recent advances of trap suppression by material design and device engineering.
Molecular engineering of covalent organic frameworks (COFs) offers an alternative approach to conventional anthraquinone oxidation via photo-induced H 2 O 2 production from O 2 reduction. Despite their potential, repo...
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Molecular engineering of covalent organic frameworks (COFs) offers an alternative approach to conventional anthraquinone oxidation via photo-induced H 2 O 2 production from O 2 reduction. Despite their potential, reported photocatalysts suffer limited proton mobility, low selectivity, and insufficient charge separation and utilization. Herein, we report a nitroxyl radical (TEMPO) decorated two-dimensional (2D) donor-acceptor (D-A)-COF photocatalyst via a one-pot strategy. Under visible light irradiation, highly crystalline TAPP-TPDA-TEMPO-COF ( TT-T-COF ) exhibits a remarkable photocatalytic H 2 O 2 yield of 10066 μmol g −1 h −1 in two-phase water-benzyl alcohol (10 % BA) system through direct two-electron (2 e − ) pathway. The mechanistic study by DFT calculations and in situ DRIFT spectra suggests Yeager-type adsorption of *O 2 ⋅ − intermediate on the nitroxyl radical site (N−O⋅). The efficient photocatalytic performance and stability of TT-T-COF are attributed to the involvement of the nitroxyl radical, which enhances selective O 2 adsorption, establishes a distinct electron density distribution, and facilitates photogenerated charge separation compared to TT-HT-COF and TT-COF counterparts. This study uncovers a new perspective for constructing metal-free, redox-mediated radical-based COFs for sustainable energy conversion, storage, and biomedical applications.
Non-fused ring electron acceptors (NFREAs), notable for their simple and economical synthesis processes, play a pivotal role in the practical deployment of organic solar cells (OSCs). However, the power conversion eff...
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Non-fused ring electron acceptors (NFREAs), notable for their simple and economical synthesis processes, play a pivotal role in the practical deployment of organic solar cells (OSCs). However, the power conversion efficiency (PCE) of NFREA based devices lags behind that of fused ring electron acceptors, because of the inferior charge transport and severe charge recombination in donor:NFREA blend films. In this study, we synthesized two novel NFREAs, A1C4-Cl and A1C6-Cl, featuring different alkyl side-chain lengths to optimize the miscibility between the donor and NFREAs for ideal morphology, taking into consideration that the morphology of donor:NFREA blend films has a significant influence on charge transport and recombination. The PBDB-T:A1C6-Cl based OSC exhibits better miscibility and more favourable phase separation, resulting in enhanced charge carrier mobilities and suppressed trap-assisted recombination. These improvements lead to a significant increase in short-circuit current density (JSC) and fill factor (FF), culminating in a PCE of 12.11% compared to PBDB-T:A1C4-Cl based devices. Our findings offer an effective approach to modulate the miscibility between donors and NFREAs, thereby enhancing the PCE of OSCs through the fine-tuning of alkyl side-chain lengths.
In clinical practice, it is not uncommon for a history of trans-urethral resection of the prostate (TURP) to complicate a future robotic-assisted radical prostatectomy (RARP). This study aims to determine if prior TUR...
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In clinical practice, it is not uncommon for a history of trans-urethral resection of the prostate (TURP) to complicate a future robotic-assisted radical prostatectomy (RARP). This study aims to determine if prior TURP adversely affects outcomes in subsequent RARP, analyzing perioperative, functional, and oncological results between the procedures. Research published in English before September 2024 was systematically reviewed using Web of Science, PubMed, Cochrane Library, and the EMBASE. Review Manager 5.4 was used to do the meta-analysis, included 15 studies, with 869 patients who underwent RARP following TURP and 5,879 patients who underwent RARP alone. Compared to standard RARP, RARP following TURP was associated with extended operative time (OT) (WMD: 26.63 min, 95% CI: 16.79-36.48, P < 0.00001), increased estimated blood loss (EBL) (WMD: 19.85 ml, 95% CI: 9.22-30.48, P = 0.0003), longer hospital stay(LOS) (WMD: 0.52 days, 95% CI: 0.28-0.77, P < 0.0001), and extended catheter removal duration (WMD: 0.18 days, 95% CI: 0.02-0.35, P = 0.03). The overall nerve-sparing success rate was lower (OR: 0.53, 95% CI: 0.35-0.78, P = 0.001), with reduced bilateral nerve-sparing success rates (OR: 0.58, 95% CI: 0.39-0.84, P = 0.005). Patients in the TURP group had higher rates of bladder neck reconstruction (OR: 8.38, 95% CI: 5.80-12.10, P < 0.0001) and major complications (Clavien grade >= 3) (OR: 1.94, 95% CI: 1.10-3.41, P = 0.02). Furthermore, the positive surgical margin (PSM) rate was elevated in the prior-TURP group (OR: 1.25, 95% CI: 1.02-1.53, P = 0.03). Quality-of-life outcomes indicated that patients undergoing RARP after TURP experienced lower urinary incontinence recovery rates at one year (OR: 0.58, 95% CI: 0.34-0.97, P = 0.04) and reduced continence recovery rates (OR: 0.60, 95% CI: 0.44-0.81, P = 0.007). Nevertheless, there were no notable differences between the two groups in terms of the rates of transfusions, unilateral nerve-sparing, lymphadenectomy, minor
Impressive short-circuit current density and fill factor have been achieved simultaneously in single-junction organic solar cells (OSCs) with the emergence of high-performance non-fullerene acceptors. However, the pow...
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Impressive short-circuit current density and fill factor have been achieved simultaneously in single-junction organic solar cells (OSCs) with the emergence of high-performance non-fullerene acceptors. However, the power conversion efficiencies (PCEs) of OSCs still lag behind those of inorganic and perovskite solar cells, mainly due to the modest open-circuit voltage (V-OC) imposed by relatively large energy loss (E-loss). Generally, E-loss in solar cells can be divided into three parts. Among them, Delta E-1 is inevitable for all photovoltaic cells and depends on the optical bandgap of solar cells, while radiative recombination energy loss, Delta E-2, in OSCs can approach the negligible value via finely matching donor with acceptor material in the blend. The relatively large non-radiative recombination energy loss, Delta E-3, becomes the main barrier to further reduce E-loss and thus enhance PCE in non-fullerene acceptor-based OSCs. In this review, the recent studies and achievements about Delta E-3 in non-fullerene acceptor-based OSCs have been summarized from the aspects of material design, morphology manipulation, ternary strategy, mechanism, and theoretical study. It is hoped that this review helps to get a deep understanding and boost the advance of Delta E-3 study in OSCs.
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